Mane moved to Bayern in 2022 with high hopes after netting 120 goals in 269 games for Liverpool.
Referee Paul Tierney missed the initial incident, but after consulting the VAR screen, he awarded United a penalty, which Bruno Fernandes duly converted.
They will face neighbours Manchester City in the finals on June 3 at Wembley Stadium.
The centre-back has been ruled out for up to three weeks with a hamstring injury.
Arsenal’s coach Mikel Arteta rang the changes in search of a leveller but they could not break Manchester City’s resistance.
Chelsea manager Graham Potter has described running the team as “probably the hardest job in football.”
The former Chelsea and Super Eagles player hung the boots after a 20 years career.
The free agent’s one-year contract will keep him with the Wolves until the summer of 2023.
Juan Mata signed a one-year contract with Galatasaray on a free transfer.
Costa is reportedly set to undergo his medical tests in England on Tuesday.
